Log of /trunk/modellib

fixes on ESySXML to get runmodel going.
* object ids are now local for read and write of XML
* ParameterSets are now written with class name
* ParameterSets linked by other ParameterSets (previously only Models) are written now
* list are now lists of str (rather than bools), lists with bool, int or float are mapped to numarray
* numarray are writen with generic types Bool, Int, Float (portability!)

modellib.WriteVTK has been rewritten. Instead of only three data objects scalar,
vector, tensor it takes now up to 20 data objects data0 ... data19 and writes it into a
single VTK file. There is also the possibilty to define individiual name tags name0,..., name19.
If no name is given the corresponding attribute name of the Link target is used.
This simplifies the usage and increases efficiency.

A few changes in the build mechanism and the file structure so scons can build release tar files:
* paso/src/Solver has been moved to paso/src
* all test_.py are now run_.py files and are assumed to be passing python tests. they can run by
scons py_tests and are part of the release test set
* escript/py_src/test_ are moved to escript/test/python and are installed in to the build directory
(rather then the PYTHONPATH).
* all py files in test/python which don't start with run_ or test_ are now 'local_py_tests'. they are installed i
by not run automatically.
* CppUnitTest is now treated as a escript module (against previous decisions).
* scons realse builds nor tar/zip files with relvant source code (src and tests in seperate files)
the python tests don't pass yet due to path problems.

+ NEW BUILD SYSTEM
This commit contains the new build system with cross-platform support.
Most things work are before though you can have more control.
ENVIRONMENT settings have changed:
+ You no longer require LD_LIBRARY_PATH or PYTHONPATH to point to the
esysroot for building and testing performed via scons
+ ACcESS altix users: It is recommended you change your modules to load
the latest intel compiler and other libraries required by boost to match
the setup in svn (you can override). The correct modules are as follows
module load intel_cc.9.0.026
export
MODULEPATH=${MODULEPATH}:/data/raid2/toolspp4/modulefiles/gcc-3.3.6
module load boost/1.33.0/python-2.4.1
module load python/2.4.1
module load numarray/1.3.3

The sparse solver can be called by paso now.
the building has been change to reduce some code redundancy:
now all scons SCscripts are importing scons/esys_options.py which
imports platform specific settings.